and Laboratory Methods. 2331 



Teleuto stage. 



7. Under low power draw a piece of wheat stem containing the black 

 patches of teleutospores. 



8. Pick out some of the teleutospores, or cut cross sections of the stem, 

 mount, and draw a number of spores under high power. Note that the spore 

 is made up of two cells. Study variation in individual spores. 



Basidium stage. 



9. It is difficult to germinate rust spores in artificial cultures. They germi- 

 nate most readily in spring when those in the field are germinating. Germinate 

 teleutospores in a drop culture and study the development of the promycelium 

 (basidium) bearing basidospores. Draw and describe. 



10. Describe in detail the mode of growth and life history of this rust, 

 noting especially the presence of heteroecism. 



XXXVII. (a) Fomes applanatus (Pers.) Wallr. 



Class, Basidiomycetes. Order, Agaricales. Family, Polyporaceae. 



This fungus is common on logs and stumps, forming semi-circular brackets 

 or shelf-like bodies from a few inches to a foot or more in width. It is of a gray- 

 ish-brown or white in color. 



1. Draw the entire fruiting body and describe. The vegetative mycelium 

 is in the wood from which the fruiting body projects. 



2. Under low power study a patch of the pores on the under side, by 

 simply laying the fungus on the stage of the microscope and focusing properly. 

 Draw. 



3. From a fresh specimen cut cross sections of a piece of the pore-bearing 

 layer, mount, and study the basidia projecting into the cavity of the pores. How 

 many spores on each basidium. Draw a single spore. 



4. Mount some of the brown, woody mycelium from the upper part of the 

 fruiting body. Draw and describe the structure of the fungus. 



5. Is the plant a parasite or a saphrophyte ? Notice the position of the 

 hymenium (pore-bearing surface) in relation to the surface of the earth. Is the 

 mycelium of the fruiting body irritable to the force of gravity ? Is there any advan- 

 tage in this ? 



(b) Polystictus chinahariniis (J acq.) Fr. 



This bracket fungus is very common on dry decaying logs and branches and 

 is easily recognized by its bright red color, especially prominent on the under 

 side. 



1. Make a sketch of the entire fruiting body. 



2. Under low power draw a patch of the lower surface showing the pores. 

 Note especially the bright red color and compare it with the red color present in 

 many flowers, fruits and roots. How do you explain the presence of the color ? 



XXXVIII. Psalliota campestris (L.) Fr. (Agaricus). Common Meadow 

 Mushroom. Class, Basidiomycetes. Order, Agaricales. Family, Agaricaceae. 



This edible toadstool grows in open, grassy places in fields and rich pas- 

 tures. The so-called " bricks " of "spawn " can be obtained from seedmen and 



